Settling tank



W. W. SAYERS El' AL SETTLING TANK Nov, 9, 1937.. 2,098,467

Filed June l5, 1935 2 Sheets-Sheet l l.. y l 7 I l Nov. 9, 1937. w. W. sAYERs Er A1. Y 2,098,467

SETTLING TANK Filed June l5, 1955 2 Sheets-Sheet 2 ttorz 613/5 puentenet-9, 1937 UNITED STATES .PATENT OFFICE i 2,098,461 y;sii'1"rr.1No. TANK wimamw. Sayers, chicago, n1., and LHmm F.

Watson, Philadelphia, Pa., assignors to Linln Belt Company, Chicago,'lll., a corporation oi' Illinois Application .num 15, 1935, serial No, 26,781,

4 claims.r (ci. 21o-.55)

This invention relates to a settling tank and has for one object to provide means for introducing liquid carrying solid matter toa settling tank in such manner that the incoming liquid stream is caused to move slowly and is`caused to spread fout and to be diiused uniformly as 'nearly as possible through the entire depth of A lthe tank or container into whichY it 'is yintronection with the influent opening, for preventing,

Vas far as possible, the formation of cross currents and particularly the formation of currents along the surface of liquid within the tank.

A still further object is to provide means in connection with the iniiuent conduit whereby the velocity o'f the influent liquid is checked and the y tendency of the liquid to boil at the center of the tank is reduced because the liquid is spread and diffused. A further object-'is to permit rapid 1, settling of the `solids because the velocity ofthe inuent is decreased and Vbecause it is spread or y 'diiusei vI-Ieretofore iniiuent has been introduced into tanks ci the type generally contemplated in the present invention, by providing a hollow column through which the 'iniiuent is carried to prac-,- tically the liquid level of liquid within the tank and then discharged at the center offthe tank' at this level. This method of introduction has a tendency to cause unnecessary agitation of the iluid within the tank and to permit the liquid andthe solids contained in the liquid to,short circuit and to pass directly to andr ovrthe yin--`2 iluent Weir around the periphery of the tank. Thus there is a tendency actually to prevent settling of the solids'and in such settling as occurs the solids must settle from a point near the surface of the liquid and they 4are required to settle throughout practicallyy the entire depth of the liquid and hence require a greater length of time to accomplish settling than that which is necessary with the short iniluent conduit shown in the present invention. Where the inuent is introduced near the surface of the liquid in the tank it is introduced atmaximum velocity" which is a disadvantage, and a greater head is required than that which is necessary where the iniiuent is introduced -below the surface or at a point relatively close to the -iloonof the tank. The invention has among its objects the avoidance of the disadvantages just mentioned.

Other objects will appear from time to time in the course ofthe spe'cication and claims.

The invention is illustrated more or less dia? grammatically in the accompanying drawings, ,Wherein.-

Figure 1 is a'generally vertical sectional view of a portion of a settling tank within which the diffuser is installed; l

Figure 2 is a generally vertical sectional detail on an enlarged scale showing the diffuser ofA Figure 1;

Figure 3 is a view generally similar to Figure 2 showing a modied form;

Figure 4 is a transverse, generally longitudinal A section taken alongv the line 4-4 of Figure 3;

Figure 5 is a view generally similar to Figures 2 and 3 showing a. modied form of diiuser;

Figure 6 is a plan or end'view of the diffuser of Figure 5;

Figure '7 is a side elevation of a further modication wherein a series of guide or deector funnels are used;

Figure 8 is a modied form where a deflector is fused with a central column;

Figure 9 is a similar detail side elevation;

Figures 10 and 11 are sections respectively along the lines lll-l0 and Il--ll of Figures 8 and 9, respectively;

Figure 12 is transverse section taken at line -'|2-|2 of Figure 8.

Like parts are designated by like characters throughout the sp'ecication and drawings.

While the apparatus of the invention is shown as applied to a round settling tankA particularly adapted furthe settling of the sludge in sewage treatment, it may be used in other associations and it may be used in connection with a tank of any size or shape, whether or not that tank be provided with skimming, conveying, sweeping or other material handling apparatus.

l is a tank which may have an annular sludge 1 may be mounted. A bridge structure 8 is carl ried upon rollers s and lll which run respectively on the tracks 6 and l. The details of the bridge structure form no part of the present invention and they are illustrated diagrammatically only A as indicating that some form of bridge structure may be positioned for movement within a tank in which the diffuser is to be installed. A sludge blade II is mounted at the bottom of the bridge structure and means are provided for causing the bridge to move about the tank and when this is done the sludge blade scrapes or cleans the bottom of the tank. An additional conveyor, indicated in dotted lines, may be mounted on the bridge structure and moves in the direction of the arrow to convey sludge toward the center of iu the tank and move it into the sludge hopper. The sludge hopper may have a cover I2 which is provided with an opening adjacent the inner end of the bridge so that material conveyed toward the hopper by the radial conveyor may pass 15 through this opening in the cover and be discharged into the sludge hopper.

Influent enters the tank through an inlet pipe or conduit I3 which is provided with an open, preferably flared discharge member I4. 'I'his inlet will cut down the velocity of the incoming sewage and give fairly good distribution. If better distribution is desired, additional apparatus may be added. A diffuser I5, having a generally conical upper and lower surface, is mounted preferably within the ared portion I4. As shown it is carried upon a post I6 which at one end, as at I1, is positioned in the inlet conduit I3 and elsewhere is braced by members I8. The diffuser proper, I5, may be adjusted up and down the rod I6 so as to be moved into and out of the. member I4 a greater or less distance as desired. As shown the adjustment is accomplished by` a collar. I9 having a set screw 20. Any adjusting means may be providedfor example, means for raising and lowering the diffuser from above. In

Figure 2, lines 2| are shown attached to the diffuser I5 and by means of them -the diffuser may be raised or lowered. The lines may be attached to any suitable attaching means.

In the modif-led form shown in Figures 3 and 4, the influent conduit, instead of having the widely, outwardly flared portion I4 is provided with a relatively slightlyflared member 22. Within it are) positioned a plurality of curved 45 blades 23. As shown these blades are fastened at their inner edges to a rod or column 24. This column may be short, as shown, or it may extend above the surface of the liquid in the tank and may then be used to support a portion of the 50 equipment in the tank. It may be used as a support for electrical equipment and as a container for an electrical conduit.

As shown in Figure 5, a further modied form of diffuser is used. In this form the member 22 5 has positioned in or near its open upper en d another type of diffuser. This comprises a plurality of inclined and curved plates 25 which are joined toward their lower ends centrally as at 2 and which are welded or otherwise securely fastened 60 to the interior of the member 22 and attheir outer edges as at 21. A conical deector 28 may or may not be positioned upon the upper endr of this diffuser and the upper end of the deiiector may be closed as indicated in full lines in Figure 6b 5 or cut off or open as indicated in dotted lines in that figure.

v It will be noted that the diffuser of Figures 1 and 2 provides for a spreading, diffusing action.

75 approximately the same as the curvature of thev spreader I4. The shape of the diffuser I5, however, may be almost infinitely varied. It might be a true cone or it might be otherwise curved and the upper surface of the diffuser I5 need not be conical as shown, but might be any other desired shape.

The diffusers of Figures 3 to 6, inclusive, provide a. lateral diffusing or spreading but provide in addition a vortex action so that the entering current of influent liquid is not only spread or diffused laterally but is additionally given a vortex movement so that as it moves into the body of the liquid within the tank it absorbs the energy of the incoming liquid and prevents cross currents toward the periphery of the tank.

It will be realized that Whereas I have herewith shown and described a practical operative device, nevertheless many changes might be made in the size, shape, number and disposition of parts without departing from the spirit of the invention and, therefore, I wish that my showing be taken as in a sense diagrammatic.

While a generally conical baille is shown in 'Figure 5, it is to be understood that this baille might be of any desired shape and it is to be further understood that a baille of this. or any other desired.` shapemight be used in connection with each of the other forms of diiusers shown in the other gures.

Where a bridge or other sludge collecting mechanism is used, such mechanism ordinarily must be caused to move about the tank and frequently it is convenient to use a motor mounted on the bridge or collector and moving with it as the driving means. Where this is the case the rod I6 may be upwardly extended, as shown in Figure l, to a point above the surface of the liquid and when so extended will carry a current collector 29. 'Ihe collector is then preferably attached to the bridge mechanism by a rigid link 30 so that as the bridge moves aboutrthe tank the collector moves with it, being drawn by the rigid link or rod 30. Frequently it is desirable to have the Vcurrent conducted to the motor in some other manner different from that shown. One other method of accomplishing the current supply is to install electric wires along the periphery of the tank and to useV trolleys or other pick-up means or as a possible further modification the current may be brought down overhead to the center of the tank and the invention is, there-4 fore, not limited to a device in which current is brought in at the center of the tank. Whether or not the rod I6 of the form of the invention shown in Figure 1 or the rod 24 of the form shownv in Figure I.3 is extended over the surface ofthe liquid in\'the tank, either to serve as a carrier for an electric connection or to serve as a support for a portion of the collector mechanism, the diffuser elements of the various forms shown operate as shown and described, that is to say, the operation of the diiIusers is not altered by the fact that the rod in question may or may not perform a function additional to that of supporting the diffuser.

In the device of'Figure 7, a series of separate conical deilectors 40, 4I are supported by brackets 42, in the mouth of the funnel I4. These deflectors are open at their centers so that the eiiluent can pass up through them and part of the stream will be deflected outwardly by the member 40 and part of the stream by the member 4I and the remainderl will pass throughl the member 4I.

In Figure 5 is shown a cross plate 50 which accents? closes the space between the deectors so that there is no possibility of a direct upward flow of any of the influent.

In the devices shown -in Figures 8, 9, and 11, is shown a modified form of structure Where the deector blades are used in connection with a central support for the collecting bridge. In 'this case the iniiuent comes in through the passage i3 as before. It discharges into an annular chamber i3 encircling the concrete column d4. This annular chamber has a curved guiding bottom coming to a peak as at l5 diametrically opposite the influent i3 so that there will bean upward non-eddying :dow of the material out through the funnel d6; thefunnel Q6 encircles the column 6d and the column dfi carries the deilector blades il located in the mouth of the funnel 36 but not in actual contact with it. l

In Figure 9, the column instead of being of concrete is a hollow metallic column 118 and the defiector blades 439 are mounted on the funnel 46.

The use and operation of our invention are v as follows:

However the diuser is associated with a tank or with a conveyor or gathering mechanism for moving the sludge, the diiusers of any of the forms shown provide means for controlling and discharging the iioW of liquid so that diffusion will take place generally throughout the entire depth of the tank andtowards the periphery, as soon as the influent leaves the deeply sub'- merged nozzle. In some forms of the invention the liquid, as it leaves the upwardly open nozzle, contacts theplurality of guide vanes which impart a rotary or vlortex*l movement to the jet of liquid and so prevent its rising directly to the surface and there blooming out to cause ow across the surface toward the edges of the tank. Such ow is to be avoided and the devices of the present invention successfully avoid it.

Whether the curved guide blades or the cone diffuser of Figures l and 2 are used, the same general result to greater; or less degree is produced.

We claim:Y 1. In combination, a shallow tank having an open top and a iiat iloor, an effluent weirabout the periphery of and adapted to control the level nozzle, deecting vanes at the discharge orice masking a portion thereof and 'curved to guide iluid discharged through the orice along radial and spiral paths as it passes into the body of the liquid.

2. In combination, a shallow tankihaving an open top, a generally ilat oor, a sludge trough .of the tank.

in the door at a point widely spaced fromv the walls, a. sludge conveyor mounted for movement adjacent the iloor and adapted to convey settled sludge to the trough. an eiuent Weir about the periphery of and adapted to control the level of the liquid in the tank, an inuent conduit extending beneath the bottom of the tank from a point outside the boundary thereof to a point adjacent the sludge trough and there continuing upwardly through the iloor, an upwardly and outwardly expanding nozzle in continuation of the conduit having its discharge orice ata point above the :door of the tank and below the liquid level as determined by said Weir, and guide means partially within and partially outside of the nozzle for gradually changing the direction of ilo'w of the eiliuent and-guiding it upwardly and outwardly toward the weir.

3. In combination, a shallow tank having an open top, a generally dat floor, a. sludge trough in the iioor at a point widely spaced from the walls, a sludge conveyor mounted for movement Vadjacent the floor and adapted to convey settled for gradually changing the direction of flow of the eilluent and guiding it upwardly and outwardly toward the Weir, such means being provided with parts directed to distribute the ow generally uniformly about the nozzle.

4. In combination, a shallow tank having an open top, a generally flat oor, a sludge trough in the floor at a point widely spaced from the walls, a sludge conveyor mounted for lmovement adjacent the oor and adapted to convey settled sludge to the trough, an eiiluent weir about the periphery of and` adapted to` control the level of the liquid in the tank, an niluent conduit extending beneath the bottom of the tank from a point outside the boundary thereof to a point adjacent the sludge trough and there continuing upwardly through the floor, an upwardly and outwardly expanding nozzle in continuation of the conduit having its discharge orifice at a. point above the floor of the tank and below the liquid level as determined by said Weir, and vanes' -at the discharge orice, masking aportion thereof,

in the path of the column of liquid discharged thereby and adapted to gradually deiiect some of the influent liquid from and direct it along spiral lines of travel toward the Ventire periphery WmLIAM w.v SAYERS; HAROLD F. WA'rsoN. 

